Creepers are platforms mounted on four or more casters having a flat or contoured upper surface to support a mechanic while he is working under an automobile. Conventionally, the creeper will have four or more casters mounted on its lower surface to allow the workman to roll about and change positions during the time he is working. A patent to Zimmerman, U.S. Pat. No. 1,104,398, discloses this broad combination and also includes a head rest and a pair of tool boxes, one on each side, for containing bolts, nuts, and the like.
A transparent shield for a similar creeper is shown in a patent to Edwards, U.S. Pat. No. 1,431,383. The shield is designed to be between the work area and the face of the mechanic to prevent tools, bolts, and the like from falling from the work area onto the facial area of the mechanic.
Reinforcing became an obvious requirement to manufacturers due to heavier workmen or use of the creeper to support heavy equipment and the patent to Hulbert, U.S. Pat. No. 2,084,957, illustrates longitudinal side pieces for strengthening in one direction and transversely oriented pieces mounted below the supporting surface to strengthen the support surface in another direction.
Woelfer received a patent, U.S. Pat. No. 2,124,389, and it illustrates a creeper made from a single piece of material except for the rollers and head rest.
The patent to Henderson, U.S. Pat. No. 2,424,032, discloses that a coaster may be formed from a single blank of plastic, metal, wood, or other materials.
The need for strengthening in mechanic's creeper was again recognized by the patent to Rose, U.S. Pat. No. 4,570,957.
What all of these patents fail to recognize is the substantial amount of labor cost in assembling the product once the various parts are available.